Roles of RNA on transcriptional and post-transcriptional regulations have raised more attention since the new era of genomics. One of the secondary structures of RNA, the RNA Gquadruplex structure, is demonstrated a relatively stable existence in human tumor cells, virus, or other species relating to diseases. G-quadruplexes are special secondary structures formed by G-rich DNA and RNA sequences that fold into a four-stranded conformation. The G-quadruplexes formed in RNA are involved in many biological process including telomere elongation, transcription regulate, pre-mRNA splicing and translation. In this review, we will give a brief introduction to the structures of RNA G-quadruplexes, the biological roles and the potential to be as drug targets.